10 Tips on How to Make Windows More Energy Efficient

If sitting by the window means you need to bundle up under the blankets or crank up the heat, then your windows aren’t doing their job well. But don’t worry—there are plenty of simple ways to increase the insulation power of your home’s windows. Even better? Several of them are DIY-friendly. Check out these 10 tips to learn how to make old windows more energy-efficient and start saving on your energy bills.

Why Make Old Windows More Energy-Efficient?

Energy-efficient windows can help save you money on your energy bills. While you might have to chip in more up front, these long-term savings can add up over time, making them a good investment. Depending on the cause of your windows’ poor energy efficiency, investing in upgrades or repairs also helps extend the lifespan of windows while maintaining comfortable indoor temperatures.  

How Much Does It Cost to Make Old Windows Energy-Efficient?

Energy-efficient windows, on average, cost between $325 and $2,000 to install. High-efficiency windows with triple-pane glass and low-emissivity (low-E) coatings can increase your cost even more. These windows cost more than standard window replacement costs, which fall between $200 and $1,200. Installation adds another $200 to $400 to your total cost. 

However, if you plan on making your old windows more energy-efficient, you might spend a different amount on expenses depending on the method. Here’s a breakdown of different costs by solution:

• Awning installation cost: $1,500–$4,600

• Window caulking cost: $100–$300

• Blinds cost: $200–$1,300

• Shades cost: $900–$2,600

• Drapes cost: $1,800–$3,000

• Shutters cost: $325–$1,300

• Window tinting cost: $325–$950

• Storm windows cost: $4,600–$20,400

How to Prep for Making Old Windows Energy-Efficient 

The best way to prepare for making old windows energy-efficient is to ensure the windows are ready for whichever method you choose to increase efficiency. Cleaning the windows, clearing space around them, and removing old screens, curtains, shutters, or blinds makes it easier for you or a pro to access the windows. This can speed up the process, saving you on installation costs if your pro charges by the hour.

How to Make Windows More Energy-Efficient

There are several methods for making old windows more energy-efficient. The method you choose will depend on the reason why your windows aren’t energy-efficient. From repairing the windows to installing window treatments to fully replacing them, you’ll need to weigh each solution to determine which route you want to take. With this in mind, here’s how to make single-pane windows more energy-efficient.

1. Replace Your Old Windows

Replacing your windows is the most effective (and, as you might expect, expensive) way to increase their energy efficiency. Window technology has improved over the years, and considering that windows typically last between 15 and 50 years, it could make sense to upgrade to newer, more energy-efficient models if yours are more than a couple of decades old.

2. Apply Window Caulk and Weatherstrips to Prevent Air Leaks

Hot and cold air can enter your home through spaces between the glass, window sash, and window frame. Caulking and weatherstripping, however, are inexpensive and easy solutions to make old windows more energy-efficient. The U.S. Department of Energy states that you can save as much as 5% to 10% on your energy bills by ensuring your home is properly weatherstripped and caulked.

If the areas near your windows feel drafty, you’ll likely need to seal them. Many types of caulking and weatherstripping materials are long-lasting—some can last anywhere from five to 20 years—but you should still check them annually to provide the best weather protection.

Apply weatherstripping to areas that can handle friction and weather changes, and apply caulk on the sides and joints of your window frame and other window areas that are stationary. If the gaps are larger, you can fill them with spray foam insulation.

3. Install Window Inserts

If you want to figure out how to improve single-pane windows, then installing window inserts is an easy way to make single-pane windows more energy-efficient—without ripping them out or adding external accessories, like awnings or blinds.

Window inserts are framed panes of glass, usually with tubing around the edges, that pop into the inside of your existing window frame. It should only take a couple of minutes to install a window insert. After you finish, you’ll instantly have another layer of protection between the interior and exterior of your home.

Depending on the shape of your window, you can either buy a custom-sized or standard-sized window insert. Not only can window inserts increase the energy efficiency of your windows, but they can also decrease outdoor noise and improve insulation.

4. Install Awnings to Block the Sun

The U.S. Department of Energy reports that awnings on southern-facing windows reduce the amount of solar heat gain in your home by as much as 65% in the summer. Awnings used on western-facing windows can reduce it by up to 77%. Installing a retractable awning means you can benefit from the warmth of the sun in the winter and protect yourself from solar heat gain in the summer, which is a win-win situation.

You can either install individual awnings over single windows or install an awning that covers a larger portion of your home to avoid individual installations. Awnings that also cover exterior walls can reduce their solar heat gain as well.

You should opt for long-lasting materials, like synthetic fabrics, which resist mildew and fading. If you’re not sure which option and sizing would lead to the most savings, find a local awning installer to help you determine the best, money-saving solutions.

5. Add Blinds, Shades, and Draperies to Block Drafts and Sunlight

Whether you prefer blinds, shades, or draperies in your home, one thing’s for sure—all of these window treatment sets can improve your window’s energy efficiency. Combining draperies and either blinds or shades maximizes the prevention of heat loss in the winter and sun protection in the summer. Not to mention, you can open all of these options to let sunlight in for warmth when it’s cold and close it up if it’s too hot outside.

Custom window treatments cost more, but a tighter fit inside or over your window will mean better protection from the outdoor air.

Let’s take a look at each option and how much window-blocking installations can save you.

Window Draperies

Drapes don’t just offer your home a pop of color and regality—insulated draperies can improve a window's energy efficiency in both the summer and winter. The thermal insulation can reduce cold drafts from coming in and reduce heat loss by as much as 10% while also preventing heat from entering your home by 33% if you use a drapery with white-plastic backings. 

Window Blinds

Window blinds are also a good choice for reducing heat gained from the sun. Quality blinds can reduce the heat by up to 45%. Blinds are not as effective for reducing heat loss in the winter, though, as they tend not to be very insulative.

Insulated Cellular Shades

For homes that have colder winters, cellular shades are a better option because they can reduce heat loss by 40% when it’s cold outside. On top of that, these types of shades can reduce solar heat gain in the winter by 60%. You can easily pull cellular shades up or down and have them custom-fitted to your windows for a clean look and maximum efficiency.

6. Apply Solar Window Film to the Glass

Solar window film is like a car sun-shield, only it’s for your home instead. This film blocks up to 35% of solar heat and 95% to 99.9% of UV rays from heating your home on a hot summer day. 

Window films can be permanent or temporary. Temporary film treatments are the best choice if you live in an area with cold winters because you can benefit from the sun warming your home during the cold season, and you might want to remove them once it starts to get cold. A permanent film—usually called window tinting—is a better option for areas that are warmer all year, but keep in mind that most window films will reduce visibility.

You can DIY a window film installation or have it done professionally by a local window replacement pro. The film costs around $8 to $15 per square foot for the materials alone. A pro knows how to measure the film and reduce air bubbles, thus improving the efficacy of the film and the look of your interior, so it’s a good idea to call in an expert.

7. Put Up Low-Emissivity Storm Panels

Low-emissivity (low-E) storm windows are extra glass panes that are installed over your existing windows to help insulate and conserve indoor heat in the winter and reflect outdoor radiant heat in the summer. As such, these windows can save you about as much money as new, double-pane windows. The best part is that they’ll also cost you around 60% less than new windows while saving you anywhere from 10% to 30% on your heating and cooling expenses.

Low-E windows are more of a permanent solution than many other energy-efficiency upgrades. For example, when comparing low-E vs. window film, the former outperforms the latter in multiple categories, including energy efficiency, appearance, and long-term reliability.

Note that the efficiency of storm panels is largely dependent on the condition of your current window setup; if your windows need some TLC, installing panels can only do so much. Also, since storm panels are manufactured from many materials, including plastic or polyethylene, not all panels provide the best visibility, so talk with a pro before you make a purchase.

8. Hang Exterior Shutters

Exterior shutters don't require space on the inside of your home. Most are made from fabric, wood, aluminum, or steel, and they work by blocking out solar heat, making them ideal for homes in hotter climates. You'll need to make sure your shutters are measured and installed properly to ensure they fit and work correctly.

You might also want to consider shutter styles that protect against heavy winds, depending on where you live. You can operate the opening and closing system from the inside of your home or via remote control.

9. Upgrade or Repair Your Window Frames

Wood window frames, especially, are prone to decay and damage over time, making it important that you inspect your window frames regularly for signs of wear. A pesky, old window frame can lead to air seepage that makes for much higher energy bills, even if you don’t have gaps around the wall opening. As such, you’ll want to repair or replace window frames as soon as possible if there is a problem.

Fiberglass and clad wood frames have the highest r-value and are the most energy-efficient window frame materials, while aluminum and vinyl are less efficient. Wood frames fall somewhere in the middle.

While you’re replacing your windows, you may want to ask an insulation company near you to install blown-in insulation around the frame while it’s exposed. Blown-in insulation can help decrease drafts coming in through the wall cavity around your window, especially if the existing insulation is older or inefficient. If you’re working with a skylight, you could opt for roof insulation instead.

10. Have a Home Energy Audit

Troubleshooting the cause of your window’s energy inefficiency can feel a little like taking a wild stab in the dark if you’re not experienced in improving your home’s energy efficiency. In this case, you’ll want to hire a local home energy auditor to evaluate your windows and other areas of the home to best conserve energy and save money. 

A home energy audit costs just over $400 on average, but low-income families may qualify for a free audit, and some state and local governments might offer rebates to offset the expenses for anyone ineligible for a free audit. And, of course, you’ll end up saving in the long run. According to the U.S. Department of Energy, reducing drafts in your home can save you between 5% to 30% yearly on your energy bills, so it pays to boost your efficiency.

What Window Materials are Energy-Efficient?

Some window materials are more energy-efficient than others—by choosing the right materials from the get-go, you can set your windows up for success when it comes to cutting energy costs. There are two elements you want to consider when choosing energy-efficient window materials: the frame and the glass.

Energy-Efficient Frames

The U.S. Department of Energy states that vinyl, wood, fiberglass, and some types of composite frames offer the most thermal resistance and are more energy-efficient window frame materials than metal. Metal clad wood frames could offer slightly less efficiency but require less maintenance than conventional wood frames.

Energy-Efficient Glass

A lot can go into making energy-efficient glass. Single-glazed windows offer the least amount of insulation, while double- and triple-glazed windows have better thermal efficiency. You can increase your insulation by installing double-pane or triple-pane windows over single-pane windows. 

Opt for low-emissivity (low-e) coatings with spectrally selective features to block out infrared radiation from the sun and further insulate your windows. Another feature worth considering is krypton gas fills, which are more efficient than argon. 

Taking Care of Energy-Efficient Windows

Once you’ve made your old windows more energy- efficient, sticking to a maintenance plan can help ensure they last as long as possible. Here are some tips on how to take care of energy-efficient windows.

• Clean the interior window panes once a week and the exterior once monthly.

• Use a gentle glass cleaner to reduce condensation and indoor moisture as needed.

• Keep the tracks clean and lubricated.

• Inspect your windows for cracks and repair them immediately.

• Repaint or reseal wooden window frames to prevent damage.

• Clean the window screen once annually to keep out pollen and insects.

• Check the weatherstripping and install new weatherstripping if it’s loose or damaged.

• Apply new caulking if the old caulking looks degraded.

• Hire a window pro to inspect your windows and handle repairs.

DIY vs. Hiring a Pro

Some energy-efficient window methods can easily be done yourself, like applying new weatherstrips, adding shades or draperies, installing window film, and hanging exterior shutters. 

For more labor-intensive solutions, like replacing the windows, adding storm panels, installing awnings, and putting in new window inserts, it’s best to work with a window installer near you. A pro can determine the best way to turn your old windows into energy-efficient windows or replace them with newer options. 

The Bottom Line

Some windows are just too old for these energy-efficient tricks to be effective. If you’ve tried everything but replacing your windows and still have higher energy bills than you’d like, it might be time to take the plunge and work with a local window installer to upgrade your windows.

When choosing the best replacement windows, look for ENERGY STAR®-qualified windows, which are designed with energy efficiency in mind. Upgrade to a more insulative frame material, like fiberglass, choose double-pane glass at the very least, and consider triple-pane glass for maximum efficiency. Additionally, have a professional install your window to ensure the wall opening is properly sealed and insulated for the best results.